parisc: add LATENCYTOP_SUPPORT and CONFIG_STACKTRACE_SUPPORT

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

1 files changed, 63 insertions, 0 deletions

diff --git a/arch/parisc/kernel/stacktrace.c b/arch/parisc/kernel/stacktrace.c
new file mode 100644
index 000000000000..2fe914c5f533
--- /dev/null
+++ b/arch/parisc/kernel/stacktrace.c
@@ -0,0 +1,63 @@
+/*
+ * Stack trace management functions
+ *
+ *  Copyright (C) 2009 Helge Deller <deller@gmx.de>
+ *  based on arch/x86/kernel/stacktrace.c by Ingo Molnar <mingo@redhat.com>
+ *  and parisc unwind functions by Randolph Chung <tausq@debian.org>
+ *
+ *  TODO: Userspace stacktrace (CONFIG_USER_STACKTRACE_SUPPORT)
+ */
+#include <linux/module.h>
+#include <linux/stacktrace.h>
+
+#include <asm/unwind.h>
+
+static void dump_trace(struct task_struct *task, struct stack_trace *trace)
+{
+        struct unwind_frame_info info;
+
+        /* initialize unwind info */
+        if (task == current) {
+                unsigned long sp;
+                struct pt_regs r;
+HERE:
+                asm volatile ("copy %%r30, %0" : "=r"(sp));
+                memset(&r, 0, sizeof(struct pt_regs));
+                r.iaoq[0] = (unsigned long)&&HERE;
+                r.gr[2] = (unsigned long)__builtin_return_address(0);
+                r.gr[30] = sp;
+                unwind_frame_init(&info, task, &r);
+        } else {
+                unwind_frame_init_from_blocked_task(&info, task);
+        }
+
+        /* unwind stack and save entries in stack_trace struct */
+        trace->nr_entries = 0;
+        while (trace->nr_entries < trace->max_entries) {
+                if (unwind_once(&info) < 0 || info.ip == 0)
+                        break;
+
+                if (__kernel_text_address(info.ip))
+                        trace->entries[trace->nr_entries++] = info.ip;
+        }
+}
+
+
+/*
+ * Save stack-backtrace addresses into a stack_trace buffer.
+ */
+void save_stack_trace(struct stack_trace *trace)
+{
+        dump_trace(current, trace);
+        if (trace->nr_entries < trace->max_entries)
+                trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
+
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+        dump_trace(tsk, trace);
+        if (trace->nr_entries < trace->max_entries)
+                trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_tsk);